The present invention relates to a dual safety switch for operating the liquid pump operating switch of a liquid sprayer, and more particularly to a safety switch including sequential actuators to prevent unintended liquid spraying.
Liquid may be sprayed from an outlet spray lance connected to a pump. The pump may be employed in an apparatus which sprays liquid at high pressure, for example, for cleaning purposes. The liquid sprayed at high pressure imparts acceleration/reaction forces to the spray lance that could cause unintended movement of the lance. Further, the spray unit vibrates in use. Such movement could naturally lead to misdirection of fluid flow and possible injury to the user or someone or something in the path of spray. Furthermore, with a high pressure sprayer, as the spray is dangerous and could harm a person or object, the spray apparatus should be protected against accidental spraying.
The pump may operate continuously, and the spray may be released by opening a valve which controls flow from the pump outlet. Alternatively, the pump may be electrically operated and may be operated only when an electric switch connected to the pump is operated to the "on" condition. It is the latter case to which the invention is directed. Means are needed for assuring that the electric switch operates the pump to spray only when the user intends.